Therm-Hazardous

Supported Applications

The ACI Hazardous Thermistor Series provides single-point temperature sensing for commercial and industrial heating and cooling building management systems. Designed as hazardous location sensors, these units are engineered for use with electronic controllers in environments requiring explosion-proof or dust-ignition proof protection.

• Wall-mounted room monitoring
• Duct air temperature measurement
• Liquid immersion sensing via thermowell integration

Operating Conditions & Performance

The series utilizes Non-Linear, NTC (Negative Temperature Coefficient) thermistor technology with a nominal response time of 10 seconds. Sensor operating ranges are defined by the element type: -40 to 150°C (-40 to 302°F) for standard Thermistors and -40 to 200°C (-40 to 392°F) for A/CP-HT models.

• Accuracy (0-70°C): ±/− 0.2 °C (±/− 0.36 °F), except A/10K-E1 Series at ±/− 0.3 °C (±/− 0.54 °F) and A/1.8K Series at ±/− 0.5 °C @ 25 °C (77 °F).
• Storage Temperature: -40 to 85°C (-40 to 185°F)
• Ambient Humidity: 10 to 95% RH, non-condensing

Hazardous Location Ratings

The enclosures meet the following hazardous location standards:

• Class I, Div. 1 & 2, Groups A, B, C, D (Explosion Proof)
• Class II, Div. 1, Groups E, F, G (Dust-Ignition Proof)
• Class II, Div. 2, Groups F, G
• Class III (Wet Locations)

NEMA & Agency Approvals

All configurations carry NEMA ratings of 3, 4, 7ABCD, and 9EFG. The series is certified to UL 1203 or UL 886 (depending on enclosure type) and CSA C22.2 No. 30 standards.

Configuration Options

The ACI Hazardous Series offers three primary configuration styles, each with specific housing materials and connection options to suit installation requirements.

Housing & Enclosure Materials

• “R” (Room) Configuration: Copper-Free Aluminum enclosure rated -50 to 60°C (-58 to 140°F).
• “D” (Duct) and “I/INW” (Immersion) Configurations: Feraloy® Iron Alloy enclosure rated -50 to 60°C (-58 to 140°F).

Sensor Elements & Outputs

Available thermistor models include A/AN, A/CP, A/CP-HT, A/1.8K, A/3K, A/20K, and A/10K-E1. Output resistances at 25°C (77°F) range from 1.8 KΩ to 100 KΩ nominal, with lead wire colors identifying the specific sensor type.

Process Connections & Probes

• Duct and Immersion probes feature a ½” NPT Male Thread process connection (or ¼” NPT for immersion without thermowell).
• Probe diameter is 0.250" (6.35mm) with 304 Stainless Steel construction.
• Immersion options include welded thermowells (“I”) or probes without thermowells (“INW”).

Electrical Connections

The series includes two, 22 AWG Etched Teflon colored lead wires (Silver Plated Copper conductors) with lengths of 14" (35.6 cm) or 24" (61 cm). Enclosures feature two ½” NPT Female Hubs for conduit entry.

Key Product Differences

Variants within the series are distinguished by their mounting configuration and probe length options:

• Hazardous Room (“R”): Wall-mounted sensors with a Copper-Free Aluminum housing. No insertion length is specified for this style.
• Hazardous Duct (“D”): Designed for duct installation, available in 4", 8", 12", and 18" probe lengths using Feraloy® Iron Alloy housings.
• Hazardous Immersion (“I” or “INW”): Intended for liquid sensing. The “I” variant includes a welded thermowell, while the “INW” variant is an immersion sensor without a thermowell (for use with existing wells). Insertion lengths of 2.5", 4", and 6" are available.

NIST certification options are available for specific models as indicated in the ordering grid.